If you're one of those worried about the battery on your expensive EV running out, look away now. Envia has unveiled a new cell that boasts a record-breaking energy density of 400Wh/kg (most currently offer between 100 and 150). It's estimated that when commercialized, this could bring the cost of a 300-mile range EV down to as little as $20,000. The performance gains come from a special manganese-rich cathode and silicon-carbon nano-composite anode combination. The battery maker is also partly owned by GM, which unsurprisingly means we're likely to see these very cells in its EVs in the future. Perhaps with the right choice of upholstery, we might see even better savings? Want to know more? Tap the fully charged press release parked just after the break.

NEWARK, Calif., Feb 27, 2012 (BUSINESS WIRE) -- Envia Systems, a technology leader in high-performance, low-cost lithium-ion energy storage solutions today announced test results that verify the company's next-generation rechargeable battery has achieved the highest recorded energy density of 400 Watt-hours/kilogram (Wh/kg) for a rechargeable lithium-ion cell. When commercialized, this 400 Wh/kg battery is expected to slash the price of a 300-mile range electric vehicle by cutting the cost of the battery pack by more than 50 percent.

The testing of Envia's next-generation lithium-ion battery was performed by the Electrochemical Power Systems Department at the Naval Surface Warfare Center (NSWC) in Crane, Ind., under the sponsorship of ARPA-E. Tests at various cycling rates at NSWC confirmed that Envia's automotive battery cell demonstrated energy density between 378-418 Wh/kg for rates between C/3 to C/10 for a 45 Amp-hour (C/3) cell. Similar cells have been cycling in Envia's test labs for over 300 cycles. NSWC Crane will also test these cells to validate cycling performance. [See excerpts of the test results here: http://enviasystems.com/announcement .]

"Since the inception of Envia, our product team has worked tirelessly and logged over 25 million test channel hours to optimally develop each of the active components of the battery: Envia's proprietary Si-C anode, HCMR cathode and EHV electrolyte," said Dr. Sujeet Kumar, Envia Systems co-founder, president & CTO. "Rather than just a proof-of-concept of energy density, I am pleased that our team was successful in actually delivering 400 Wh/kg automotive grade 45 Ah lithium-ion rechargeable cells."

"Envia's new battery technology represents exactly the kind of innovation and breakthroughs that ARPA-E is looking for from the American research and development community," said ARPA-E Director Arun Majumdar. "We hope that this low cost and high density battery technology enables wide spread adoption of electric vehicles across the country and around the world."

"In an industry where energy density tends to increase five percent a year, our achievement of more than doubling state-of-art energy density and lowering cost by half is a giant step towards realizing Envia's mission of mass market affordability of a 300-mile electric vehicle," said Envia Systems Chairman and CEO Atul Kapadia.